ENR 1.7 ALTIMETER SETTING PROCEDURES
1. Introduction
The altimeter setting procedures in use generally conform to those contained in ICAO Procedures for Air Navigation Services - Aircraft Operations (ICAO Doc 8168, OPS/611 (PANS-OPS)) Vol. I. Part III. Section 1.
These procedures are applied to all IFR and VFR flights operating within the Budapest FIR.
The atmospheric pressure is measured in accordance with ICAO Annex 3 Chapter 4, paragraph 4.11.
QNH and QFE values are computed in tenths of a hectopascal (hPa). On pilots' request it may be given in millimetres and tenths.
In routine reports disseminated at the aerodrome, QNH is included regularly while QFE is available on request from ATS units.
The values are rounded to the nearest lower whole hectopascal. For example, QNH 995.6 hPa is given as “QNH 995".
In plain language reports ((ATIS and VOLMET) broadcast), the unit of measurement (hPa) is omitted.
2. Basic altimeter setting procedures
2.1 General
2.1.1 System of flight levels
- Flight level zero is located at the atmospheric pressure level of 1013.2 hPa. Consecutive flight levels are separated by a pressure interval corresponding to at least 1 000 FT (300 M) in the Standard Atmosphere.
- Flight levels are numbered according to the following table, which indicates the corresponding height in the Standard Atmosphere in feet and the approximate equivalent height in metres.
| Flight Level Number | Height in the Standard Atmosphere | |
|---|---|---|
| Feet | Metres | |
| 100 | 10 000 | 3 050 |
| 150 | 15 000 | 4 550 |
| 200 | 20 000 | 6 100 |
| 660 | 66 000 | 20 100 |
2.1.2 Transition altitude
The transition altitude specified for the Budapest FIR is 10 000 FT (3 050 M).
2.1.3 Transition level
The transition level will be determined by the appropriate ATC unit so as to give a transition layer of at least 1000 FT (300 M) vertical separation above the transition altitude.
For determination of current transition level the following table is used.
| Transition altitude | QNH hPa | Transition level | |
|---|---|---|---|
| Feet | Meters | ||
| 10 000 | 3 050 | 1013.3 and above | FL110 |
| 1013.2 - 977.2 | FL120 | ||
| 977.1 and below | FL130 | ||
The transition level at Budapest Liszt Ferenc International Airport is normally transmitted in the ATIS broadcast, or is advised in the clearances as appropriate.
2.1.4 Transition from flight levels to altitudes and vice versa
The vertical position of aircraft when at or below the transition altitude shall be expressed in terms of altitude, whereas a position at or above the transition level shall be expressed in terms of flight level. While passing through the transition layer, vertical position shall be expressed in terms of flight levels in climb and in terms of altitude when descending.
2.2 Take-off and climb
The QNH value for the altimeter setting is normally transmitted in the ATIS broadcast, or is advised in start- up clearance as appropriate.
2.3 Vertical separation - en route
2.3.1 Vertical position
- The vertical position of aircraft during the en route phase of flight, at and below the transition altitude, shall be expressed in terms of altitude.
- The vertical position of aircraft during the en route phase of flight, at or above the transition level shall be expressed in terms of flight level.
- In air-ground communication, the vertical position of an aircraft during en route flight shall be expressed according to the altimeter setting applied to conform with the provisions of the above paragraphs, as appropriate.
- The following vertical separation minima are applied:
- 1 000 FT (300 M):
- Below FL290 (8 850 M STD)
- In EUR RVSM airspace between RVSM approved ACFT.
- 2 000 FT (600 M):
- In EUR RVSM airspace between non-RVSM approved ACFT and any other ACFT.
- In EUR RVSM airspace between state ACFT performing formation flight and any other ACFT.
- Between military aircraft flying at supersonic speed and any other ACFT.
- A minimum separation of 2 000 FT (600 M) shall be applied in EUR RVSM airspace between an ACFT experiencing radio communication failure and any other ACFT in the vicinity.
2.3.2 Terrain clearance
- The QNH altimeter setting and temperature information are included in routine reports for use in determining adequate terrain clearance. These data are transmitted normally in ATIS and VOLMET broadcasts and are also available on request from ATIS units.
- Normally, the QNH value determined for Budapest Liszt Ferenc International Airport is used as the “regional QNH” within the Budapest FIR.
- ATC units determine the lowest usable flight level for the whole of the part of the control area for which they are responsible, use it when assigning flight levels and pass it to pilots on request.
Note: The objectives of the ATC services as prescribed in ICAO Annex 11, do not include the prevention of collision with terrain. The procedures prescribed above do not, therefore, relieve the pilots‘ of their responsibility of ensuring that any clearances issued by ATC units are safe in the respect, except when an IFR flight is vectored by radar.
- When vectoring an IFR flight, the radar controller shall ensure adequate terrain clearance at all times until the aircraft reaches the point at which the pilot will resume his/her own navigation.
2.4 Approach and landing
The QFE value given in clearances of ATC units shall be related to the threshold elevation of the runway in use.
E.g.: QUEBEC - FOXTROT - ECHO FOR RUNWAY THREE - ONE - RIGHT IS NINER - NINER - TWO
Note: This does not preclude the use of the QFE altimeter setting by a pilot for terrain clearance purposes during the final approach.
If an approach clearance is given to ACFT operating above the transition level, the clearance shall include the transition level.
